Credit

Caption

A section of the accelerator mass spectrometer (AMS) in the Oxford Radiocarbon Accelerator Unit, for dating samples of organic material. In this section a stream of positively charged carbon ions flowing inside the main tube is kept in position by electrostatic lenses before the isotopes are separated, with carbon-14 ions counted by a detector. This count is the basis for calculating the age of the original sample by comparison with the more stable carbon-12 and carbon 13 atoms. Photographed at the Oxford Radiocarbon Accelerator Unit, University of Oxford, UK.